Studies are projected to compare the endocrine function of the in situ uterus and ovary and the autotransplanted ovine uterus and ovary. Interrelationships in the utero-ovarian pituitary system will be examined and in addition regulatory mechanisms and interactions of hormones in their target organs will be investigated and compared in the in situ and transplanted organs. Possible mediating or modulating roles of the sympathetic nervous system will thus be determined. The sequential release of prostaglandins and/or steroids from these organs will be determined by specific and sensitive radioimmunoassays and in addition the role of substances thought or known to mediate hormonal and blood flow changes will be determined by the use of selective inhibitors and other drugs. In this way the sequential relationships, the interactions, the synergisms or antagonisms will be revealed and may aid in the assigning of specific roles to these mediating agents. Among the substances to be measured are steroid and polypeptide hormones, histamine and other biogenic amines, 3'5'-AMP and A, E, and F series prostaglandins and some of their metabolites. In addition a variety of gross and fine structural studies will be carried out on both types of organs to determine normality and viability in the autotransplanted organs and to assist in the elucidation of mechanisms and responses within the transplants and within the in situ organs. Bibliographic references: Einer-Jensen, N., and McCracken, J.A. (1975) "Krypton 85 measurement of capillary blood flow in the ovine corpus luteum during PGF2 alpha-induced luteolysis." Abstract, Internat. Conf. on Prostaglandins. p. 109. Roberts, J.S., B. Barcikowski, L. Wilson, R.C. Skarnes and J.A. McCracken (1975) "Hormonal and related factors affecting the release of Prostaglandin F2 alpha from the uterus." J. Steroid Biochemistry, 6, 1091-1097.